无聊的我反汇编,MessageBox 函数

1 user32_MessageBoxA:
USER32:7754EA11 mov     edi, edi
USER32:7754EA13 push    ebp
USER32:7754EA14 mov     ebp, esp
                                                   
USER32:7754EA16 cmp     dword_77559A74, 0                  
USER32:7754EA1D jz      short loc_7754EA43   分支1
USER32:7754EA1F mov     eax, large fs:18h
USER32:7754EA25 push    0
USER32:7754EA27 push    dword ptr [eax+24h]
USER32:7754EA2A push    offset unk_77559EA4
USER32:7754EA2F call    off_774F1434           CALL1   这个地方的函数为interlockedcompareexchage();
USER32:7754EA35 test    eax, eax
USER32:7754EA37 jnz     short loc_7754EA43         分支2
USER32:7754EA39 mov     dword_77559EA0, 1
USER32:7754EA43
USER32:7754EA43 loc_7754EA43:                           ; CODE XREF: USER32:user32_MessageBoxA+Cj
USER32:7754EA43                                         ; USER32:user32_MessageBoxA+26j
USER32:7754EA43 push    0
USER32:7754EA45 push    dword ptr [ebp+14h]
USER32:7754EA48 push    dword ptr [ebp+10h]
USER32:7754EA4B push    dword ptr [ebp+0Ch]
USER32:7754EA4E push    dword ptr [ebp+8]
USER32:7754EA51 call    near ptr user32_MessageBoxExA                  
USER32:7754EA56 pop     ebp
USER32:7754EA57 retn    10h

反汇编C语言复原
令dword_77559A74 用变量a来表示
令 dest=offset unk_77559EA4
令 b=eax+24h
令 c= dword_77559EA0
if(a!=0){
    if(!interlockedc0mpareexchage(dest,b,0))
        c=1;
}
MessageBoxExA();